Grace Period for Elimination of Flats in Sacks
January 22 2023

Grace Period for Elimination of Flats in Sacks

Posted By | Tina Jeremiah
Posted On | January 22 2023

Grace Period for Elimination of Flats in Sacks

As part of its network redesign efforts, the Postal Service is eliminating the use of SACKS as containers for Flats but will continue to allow Flat trays as acceptable containers along with bundles on pallets for USPS Marketing Mail and Periodical Flat Mail or other classes. 

Some exceptions will be made. The exception to this is that the carrier route, 5-digit scheme carrier routes and 5-digit carrier routes flat mail will continue to be allowed to use sacks as a handling unit.  For mail entered at Delivery Units, no container is needed. Bundles can be entered directly.  The 100-pound weight minimum for pallets destined for mixed ADC destination will be eliminated so mailers can put bundles on pallets for these sparsely-distributed destinations.

On Friday, January 20, 2023, the USPS announced how the grace period for the Flats in Sacks Elimination will function. (

This grace period is in effect from now until February 21st, when the requirements for flat preparation in flat trays will be strictly enforce for Marketing Mail and Periodical Mail.  While this grace period is in effect, sacks will continue to be an acceptable handling unit when preparing flats.  However, the USPS recommends conforming to the new requirements as soon as possible.

If possible, switching all production from sacks or trays on pallets to pure bundles on pallets will allow you the most flexibility and efficiency.

If you  need to use the exception provided by the grace period, please note the additional requirements the USPS communicated with their announcement:

  • Contact your Business Mail Acceptance clerk for specific answers about your need for an exception.
  • Note that a workaround exists to submit a Mail.dat to PostalOne! by manually modifying the container type to allow acceptance.
  • Note the additional paperwork needed to be filled out when submitting mail prepared in sacks but charged as trays for Periodicals on the 3541 Postage Statement.

If you use BCC Post Presort or WindowBook DATMAIL, see below for some helpful articles on how to manually change a Mail.dat to satisfy these instructions for workarounds.

We are here to help!

After contacting your Business Mail Acceptance Clerk, if you have specific questions on how to take the necessary steps in our BCC software, reach our to our support department.

You can get more information by calling us at (877) 971-1500.

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